Direction of rotation responsive switch



Feb. 20, 1940. A, SATTERLEE 2,190,682

DIRECTION OF ROTATION RESPONSIVE SWITCH Filed Nov. 17, 1956 f 36 INVENTOR. HOWARD A. SATTERLEE .5 1000/5 K B Y W H; Load Circul'f ATTORNEY.

Patented Feb. 20, 1940 UNITED STATES PATENT OFFICE DIRECTION OF ROTATION RESPONSIVE SWITCH Application November 1'], 1936, Serial No. 111,272

3 Claims.

The present invention is a continuation in part of applicants prior application, Serial No. 1,032, filed January 9, 1935, and entitled Method and apparatus for the measurement of rotational 5 velocities, now Patent No. 2,088,613, dated. August 3, 1937.

The present invention relates to the indication of the direction of rotation of a rotating shaft and to apparatus for performing a switching operation whenever the shaft reverses its direction of rotation.

In the above mentioned application I have described a method and apparatus for measuring and indicating the velocity of a rotating shaft.

The system described in that application makes possible a substantially instantaneous indication of the shafts speed produced by means of a stationary index.

The present invention provides a device whereby an indication of the direction of rotation of a rotating shaft can automatically be obtained and furthermore whereby any desired switching operation when the shaft reverses its direction of rotation may be effected.

My invention will best be understood by consideration of the following description and of the accompanying drawing in which Figure 1 shows a perspective view of a simple form of the invention and Figure 2 shows a modification of Figure 1.

As shown in Figure 1, 19 indicates the shaft whose speed is to be measured. This shaft is geared by suitable gearing 17., E8 to an auxiliary shaft L5. The shaft I5 consequently reverses its direction whenever the shaft 19 reverses its direction. Mounted on the shaft i5 is a rotary contact element 20 having a conducting segment 31 with which cooperate pairs of brushes 2? and 28. When the conducting segment 31 passes under either of these pairs of brushes, the brushes of that pair are short-circuitedL If the brushes be included in an electrical circuit, the circuit must be closed for a brief period of time.

Now for the purpose of selecting one or the other of the sets of brushes 2'! or 28 or for the purpose of closing or opening any desired electrical circuit when the shaft reverses its direction of rotation a special device is provided in 50 accordance with the present invention. This device includes a friction collar 2| which comprises two blocks of wood 29 held against the shaft by means of a phosphor bronze spring member 30 with just sufficient force when the shaft rotates to produce a small torque on the spring member so that its lower end 3| which carries the contact 32 will be moved to the left or to the right.

When the contact 32 is moved to the left, it makes contact with the stationary contact 33. Thus, when the shaft is rotating in one direction, 5 i. e., clockwise, the contacts 32, 33 will be closed while, when the shaft rotates counter-clockwise, the contacts will be open. The contacts 32. 33 may be connected in circuit with an electromagnet 34 of the relay 35 and energized from any suitable power source. The relay 35 may, for example, be provided with any desired number of armatures, for example, and 48. When the magnet 34 is not energized, the armature 45 is held against contact 46 while at the same time the armature 48 is held against contact 49. On the other hand, when the electromagnet 34 is energized by the closing of the contacts 32, 33 the armature 45 is held against the contact 44 and the armature 48 is held against contact 41.

If the armature 45 and contact 46 are connected as shown to form the ends of a series circuit including the indicating lamp 36 and a source of power, the lamp 36 will be illuminated for one direction of rotation of the shaft and extinguished for the reverse direction of rotation. Likewise, another lamp connected in series with the source of power to contact 44 and armature 45 will indicate by its illumination the reverse direction of rotation. In a similar manner, the armature 48 and the contacts 47 and 45 may, as shown, be connected to the brushes Zl'and 28 on the contact element 25 whereby one or the other set of brushes is automatically selected for one or the other direction of rotation of the shaft. The brushes 2! and 28 may be employed in my speed 'measuring system described in my above mentioned copending application or may be employed for any other desired purpose.

In the modification of Fig. 2 only the auxiliary shaft l5 has been shown. On the shaft are mounted two metal face plates 50 and 5| by means of screws 52, 53 respectively. Bearing against these plates and loosely mounted on the shaft are the discs 54 and 55 respectively which may conveniently be made of wood. These blocks are held in frictional engagement with the respective plates by means of the spring 56. Slots 5! and 58 are cut in the discs 54 and 55 respectively into which fit the ends of a rod 59 which is at its center supported by the lever lit. The latter is in turn supported at "i by the rod 62 which is mounted by the bearings 53 and 84 in vertical projections 55 and 55 of a frame member 51. The lever is firmly fixed to the shafts 59 55 and 82 so that the latter turns with the lever. The lever 80 is provided at its upper endwith a slot 68 which engages a bar 68. The latter by means of a longitudinal slot 10 engages the ends of any desired number of movable switch members H, l2, I8, 14. The latter carry contacts adapted to cooperate with a lower set of contacts 15 to 18 and with an upper set of contacts 18 to 82. At the ends of the rods 82 are mounted sets of brushes 83 and 84 which cooperate with the rotary contact elements 85 and 88 respectively. The latter are provided with conducting segments 81 and 88. The lower end of the lever 60 terminates in a right-angle portion 88. Beneath the end of the portion 88 there is mounted on the frame 81 a U-shaped element 88 having the adjusting screws 9| and 92. When the shaft I5 rotates in one direction, say, counter-clockwise, the friction between the plates 50, El and the discs 54, tends to rotate the latter in a counter-clockwise direction. The rod 58 whose ends are engaged in the slots 57, 58 likewise tends to rotate in the same direction. Such rotation is limited, however, by the abutment of the portion 89' of the lever against the screw 8| as shown in Fig. 2.

Similarly when the shaft it rotates in the opposite or clockwise direction the discs 64, 55 rotate in this direction until element 89 strikes the screw as, The motion of the lever 80, when the shaft l5 reverses its direction in this manner, causes its forked end to bring about the raising of the bar 88 thereby causing the movable switch members it to 79 inclusive to leave the lower contacts 55 to 18 inclusive and make contact with the upper contacts it to d2 inclusive. This motion of the lever lit likewise causes the rotation of the rod 82 so that the brushes 83 are removed from the contactelement 35 while the brushes M are brought to bear against the contact element as.

Similarly to Fig. l, the direction of rotation Having now described my invention, what I claim is:

1. Apparatus responsive to the direction of rotation of a shaft including, in combination, a pair of rotary contact elements secured to said shaft, two sets of brushes cooperating with said contact elements respectively and means frictionally actuated by motion of said shaft for removing one set of brushes from contact with its contact element and placing the other set of brushes in contact with its contact element whenever the shaft reverses its direction of motion.

2. Apparatus responsive to the direction of rotation of a shaft including, in combination, a pair of abutments secured to the shaft, a spring, a pair of friction discs mounted on said shaft so as to be rotatable with respect thereto and urged against said abutments by said spring, a plurality of contact means, a lever mechanism operated by partial rotation of said friction discs and thereby operating the said contact means, a pair of rotary contact elements also secured to said shaft, two sets of brushes cooperating with said contact elements respectively and means actuated by said lever mechanism for removing one set of brushes from contact with its contact element and placing the other set of brushes in contact with its contact element whenever the shaft reverses its direction of motion and simultaneously with the operation of said first contact means.

3. Direction of rotation-responsive switch including, in combination, a shaft, 8. pair of abutments secured to said shaft spaced a short distance apart, a pair of friction discs surrounding said shaft, one of said discs frictionally engaging each of said abutments, a spiral spring around said shaft between said discs, thereby pressing each disc against its corresponding abutment, a bar extending parallel to the axis of said shaft into apertures in said discs, a pivoted lever having its long arm fixed to said bar, contact means and means engaging the short arm of said lever for operating said contact means in response to partial rotation of said discs.

HOWARD AVERY SAT'I'ERLEE. 

